Spanish slang term. When you eat something and some time later you discover a piece of what you ate in your teeth.
It stands for "for later"

Para luego -> Paluego

Jack: Do you remember that girl who were eating popcorn 2 days ago at the restaurant?
Ryan: Yeah!! That booty girl!
Jack: I kissed her yesterday and I touched something resident in her teeth, so I runaway almost puking and I discovered a paluego of popcorn on my tongue!!
Ryan: Oh my god!